1. Field of the Invention
The present invention is related to a cover which covers a case of a busbar module installed to batteries of electric vehicles including hybrid cars. Particularly, the present invention relates to the integration of an insulative cover which covers the electrified parts of busbars which tie battery cells in series with a wire protecting cover which protects the wires of voltage detecting terminals for voltage detection of the battery cells.
2. Description of the Related Art
The PTL 1 discloses a cover structure which includes insulative covers which cover the electrified parts of busbars which connect battery cells in series, and a wire protecting cover which protects wires of voltage detecting terminals for voltage detection of the battery cells.
FIG. 9 is a whole perspective view which shows one embodiment of the cover structure of the power supply device according to the PTL 1. FIGS. 10A and 10B are top views of a case which shows main parts of the cover structure of FIG. 9. FIG. 10A shows that the cover is taken off from the case, and FIG. 10B shows that the cover is closed onto the case.
In FIGS. 9 to 10B, a power supply device 1 includes a plurality of board-like batteries 3 which are arranged in a row to form a battery 2, and a busbar module 4 which is installed onto the battery 2.
Each of the batteries 3 includes a positive electrode and a negative electrode at an upper end. When the front side of a battery 3 is arranged with a positive electrode and the back side of the battery 3 is arranged with a negative electrode, the front side of an adjacent battery 3 is arranged with a negative electrode and the back side of the adjacent battery 3 is arranged with a positive electrode so that the positive electrode of the front side of the battery 3 are connected in series with the negative electrode of the front side of the adjacent battery 3 with a rectangular board-like busbar 5 of FIG. 10A. The electrode at a right-side end penetrates through holes 5a and 13a of the busbar 5 and a terminal 13, projects upwards into a busbar accommodating part 16, and is connected mutually with a clamping nut. The adjacent electrode penetrates through a hole 5a at a left half part of the busbar 5, and is connected with a clamping nut similarly.
The busbar module 4 includes a case 7 made of insulative resin in which the busbars 5 made of conductive metal and thermistors 6 for detecting temperature are installed, and covers 8 made of insulative resin which are installed onto the case 7.
As shown in FIG. 10A, the case 7 includes a plurality of rectangular frames-like busbar accommodating parts 16, a voltage detection wire accommodating part cover 14 which is coupled to the front sides of the busbar accommodating parts 16 with thin flexible walls 17, thermistor accommodating parts 18 integrally following the back sides of the busbar accommodating parts 16, and an oblong belt-like thermistor wire accommodating part 19 integrally following to the back sides of the thermistor accommodating parts 18.
Each of the covers 8 is roughly L-shaped or roughly U-shaped, and arranged at the front side of the electrodes and the busbar 5 at the front side in FIG. 9.
Each of the covers 8 can be freely and independently opened and closed. One thermistor 6 and wires 10 derived from the thermistor 6 are arranged in the case 7 for each of the covers 8. In this example, the thermistors 6 are arranged with a ratio of one thermistor 6 for four batteries 3, and each of the cover 8 covers to protect four electrodes and two busbars 5 corresponding to the four electrodes as well as the thermistor 6 and the wires 10 derived from the thermistor 6 at the same time.
Each of the covers 8 is locked to a locking part 12 of the case 7 with a right locking part 11 and a left locking part 11. A reference number 13 in FIG. 9 is a punched hole for the locking part 11.
In front of the cover 8, the voltage detection wire accommodating part cover 14, which accommodates wires that follow the terminals 13 for voltage detection which are connected to the busbars 5 (FIG. 10A), are formed into an oblong trough-like shape, and the wires for voltage detection are derived from the right and left ends of the case 7 collectively to the outside together with the derived wire 10 for temperature detection.
Each of the busbar accommodating parts 16 includes a frames-like vertical peripheral wall (including front, back, right and left walls) 16, and a horizontal bottom wall 16a having a hole through which electrodes pass. The left end of the peripheral wall of one busbar accommodating part 16 is coupled to the right end of the peripheral wall of an adjacent busbar accommodating part 16 with a flexible hinge 20. The busbar 5 is locked with nails 16b in the peripheral wall, and the voltage detection terminal 13 touches on the top surface at the right half of the busbar 5 and is locked with nails 16b similarly.
The thermistor accommodating parts 18 are disposed in predetermined spaces between the busbar accommodating parts 16 and the thermistor wire accommodating part 19 at the back side. The thermistor accommodating part 18 has a narrow width in the front-to-back direction which is around 2 times the thickness of the thermistor 6, and a length in the left-to-right direction which is slightly longer than the full length of the thermistor 6 in the left-to-right direction. The thermistor accommodating part 18 couples the bottom side of the busbar accommodating part 16 with the bottom side of the thermistor wire accommodating part 19. The thermistor accommodating part 18 is disposed to be lower than the busbar accommodating parts 16 and the thermistor wire accommodating part 19. The wires 10 derived from the thermistor 6 go through vertical right and left ribs 28, and are guided between horizontal right and left ribs 31 of the thermistor wire accommodating part 19, bent from the terminal ends of the right and left ribs 31 to the left side in FIG. 10A and guided along a bent part 32. Then the wires 10 derived from the thermistor 6 are held between a pair of claw parts 33, wired along a horizontal wall (base wall) 30 to the end of the case 7, and derived from the ends of the case 7 to the outside together with other wires for voltage detection as shown in FIG. 9. In this state, as shown in FIG. 10B, the covers 8 are installed onto the case 7, and the busbar 5, the terminals 13 for voltage detection, the thermistors 6 and the derived wires 10 of the thermistors 6 of FIG. 10A are covered to be safely insulatively protected from external interferences.